A handle, transaction ID, or other token of
agreement between cooperating programs. "I give him a packet, he
gives me back a cookie." The claim check you get from a
dry-cleaning shop is a perfect mundane example of a cookie; the
only thing it's useful for is to relate a later transaction to this
one (so you get the same clothes back). Compare magic cookie;
see also fortune cookie. Now mainstream in the specific sense
of web-browser cookies.
